Accuracy and reliability of naevus self-counts

The Level of Agreement between Self-Assessments and Examiner Assessments of Melanocytic Nevus Counts: Findings from an Evaluation of 4548 Double Assessments

Cutaneous melanoma (CM) is a candidate for screening programs because its prognosis is excellent when diagnosed at an early disease stage. Targeted screening of those at high risk for developing CM, a cost-effective alternative to population-wide screening, requires valid procedures to identify the high-risk group. Self-assessment of the number of nevi has been suggested as a component of such procedures, but its validity has not yet been established. We analyzed the level of agreement between self-assessments and examiner assessments of the number of melanocytic nevi in the area between the wrist and the shoulder of both arms based on 4548 study subjects in whom mutually blinded double counting of nevi was performed. Nevus counting followed the IARC protocol. Study subjects received written instructions, photographs, a mirror, and a "nevometer" to support self-assessment of nevi larger than 2 mm. Nevus counts were categorized based on the quintiles of the distribution into five levels, defining a nevus score. Cohen's weighted kappa coefficient (κ) was estimated to measure the level of agreement. In the total sample, the agreement between self-assessments and examiner assessments was moderate (weighted κ = 0.596). Self-assessed nevus counts were higher than those determined by trained examiners (mean difference: 3.33 nevi). The level of agreement was independent of sociodemographic and cutaneous factors; however, participants' eye color had a significant impact on the level of agreement. Our findings show that even with comprehensive guidance, only a moderate level of agreement between self-assessed and examiner-assessed nevus counts can be achieved. Self-assessed nevus information does not appear to be reliable enough to be used in individual risk assessment to target screening activities.

Role of community pharmacists in skin cancer screening: A descriptive study of skin cancer risk factors prevalence and photoprotection habits in Barcelona, Catalonia, Spain

Background:

Skin cancer incidence is increasing alarmingly, despite current efforts trying to improve its early detection. Community pharmacists have proven success in implementing screening protocols for a number of diseases because of their skills and easy access.

Objective:

To evaluate the prevalence of skin cancer risk factors and the photoprotection habits with a questionnaire in community pharmacy users.

Methods:

A research group consisting of pharmacists and dermatologists conducted a descriptive cross-sectional study to assess photoprotection habits and skin cancer risk factors by using a validated questionnaire in 218 community pharmacies in Barcelona from May 23^rd to June 13^th 2016. All participants received health education on photoprotection and skin cancer prevention. Patients with ≥1 skin cancer risk factor were referred to their physician, as they needed further screening of skin cancer.

Results:

A total of 5,530 participants were evaluated. Of those, only 20.2% participants had received a total body skin examination for skin cancer screening in the past by a physician and 57.1% reported using a SPF 50+ sunscreen. 53.9% participants presented ≥1 skin cancer risk factor: 11.8% participants reported having skin cancer familial history and 6.2% reported skin cancer personal history; pharmacists found ≥10 melanocytic nevi in 43.8% participants and chronically sun-damaged skin in 21.4%. Lesions suspicious for melanoma were reported in 10.9% of the participants and urgent dermatological evaluation was recommended.

Conclusions:

Pharmacists can detect people with skin cancer risk factors amongst their users. This intervention can be considered in multidisciplinary strategies of skin cancer screening.

Monitoring of naevus density at age 6: Is it both feasible and meaningful?

BACKGROUND

Instruments for the evaluation of campaigns targeting the reduction of UV exposure in the population, and thus skin cancer risk, are needed.

OBJECTIVE

To examine the "childhood monitoring of naevus density" approach suggested some 10 years ago in a routine setting of mandatory pre-school examinations.

METHODS

Data were collected between 1999 and 2005 in Göttingen, Wolfenbüttel, Northeim, Salzgitter, and Erlangen. Besides basic data, freckling, iris and hair colour, and "Fitzpatrick skin type" as well as counts of melanocytic naevi were documented. Negative binomial regression analysis quantified the association between naevus counts and above factors, and year and site of examination, respectively.

RESULTS

Of 12,809 children examined at five different sites over a period of 6 years, 11,345 were eligible for the analysis. While differences between sites were marked and significant, only a very minute, albeit significant, decrease in risk was found between the reference group (Göttingen 1999/2000) and the last year examined in Göttingen (2005).

CONCLUSIONS

Significant between-site variation in the analysis adjusted for constitutional factors points to problems with standardization; thus, a broad application of this instrument does not seem to be advisable.

Correspondence between pigmented lesions identified by melanoma patients trained to perform partner-assisted skin self-examination and dermatological examination

BACKGROUND

Skin self-examination (SSE) training interventions can increase understanding of melanoma early detection criteria and promote SSE. However, there remains a need to evaluate whether intervention participants can apply such early detection skills to accurately identify concerning, or potentially malignant, pigmented lesions during full body SSE.

METHODS

We assessed SSE accuracy using data from a randomized control trial of a SSE skills training intervention designed to promote partner-assisted SSE among melanoma patients. In the trial, patient-partner pairs were administered the training intervention and performed monthly SSE to identify, evaluate, and track concerning pigmented skin lesions. Patients received a total body skin examination by a dermatologist approximately 4-months postintervention. SSE accuracy was assessed as the correspondence between the specific concerning pigmented lesions identified by 274 study pairs during SSE with those identified during dermatological examination. We also examined whether lesions that were biopsied during the study were identified prior to biopsy during SSE.

RESULTS

Approximately three in four of the concerning lesions identified by pairs during SSE were also identified during the dermatological exam. There were 81 biopsies performed during the study and pairs had identified 73% of the corresponding lesions during SSE. Of the five melanoma detected, three were identified during SSE.

CONCLUSION

Melanoma patients and partner taught to do SSE using an evidence-based program developed a high degree of correspondence with the study dermatologist in identifying concerning lesions.

IMPACT

This study provides novel evidence that supports the accuracy of full-body SSE for the patient identification of concerning lesions.

A permutation test to analyse systematic bias and random measurement errors of medical devices via boosting location and scale models

Measurement errors of medico-technical devices can be separated into systematic bias and random error. We propose a new method to address both simultaneously via generalized additive models for location, scale and shape (GAMLSS) in combination with permutation tests. More precisely, we extend a recently proposed boosting algorithm for GAMLSS to provide a test procedure to analyse potential device effects on the measurements. We carried out a large-scale simulation study to provide empirical evidence that our method is able to identify possible sources of systematic bias as well as random error under different conditions. Finally, we apply our approach to compare measurements of skin pigmentation from two different devices in an epidemiological study.

Accuracy of self-reported nevus and pigmentation phenotype compared with clinical assessment in a population-based study of young Australian adults

BACKGROUND

Awareness of individual risk may encourage improved prevention and early detection of melanoma.

METHODS

We evaluated the accuracy of self-reported pigmentation and nevus phenotype compared with clinical assessment, and examined agreement between nevus counts from selected anatomical regions. The sample included 456 cases with invasive cutaneous melanoma diagnosed between ages 18 to 39 years and 538 controls from the population-based Australian Melanoma Family Study. Participants completed a questionnaire about their pigmentation and nevus phenotype, and attended a dermatologic skin examination.

RESULTS

There was strong agreement between self-reported and clinical assessment of eye color [κ, = 0.78; 95% confidence interval (CI), 0.74-0.81]; and moderate agreement for hair color (κ = 0.46; 95% CI, 0.42-0.50). Agreement between self-reported skin color and spectrophotometer-derived measurements was poor (κ = 0.12; 95% CI, 0.08-0.16) to moderate (Spearman correlation rs = -0.37; 95% CI, -0.32 to -0.42). Participants tended to underestimate their nevus counts and pigmentation; men were more likely to underreport their skin color. The rs was 0.43 (95% CI, 0.38-0.49) comparing clinical total body nevus counts with self-reported nevus categories. There was good agreement between total body nevus counts and site-specific nevus counts, particularly on both arms.

CONCLUSIONS

Young adults have suboptimal accuracy when assessing important risk characteristics including nevus numbers and pigmentation. Measuring nevus count on the arms is a good predictor of full body nevus count.

IMPACT

These results have implications for the likely success of targeted public health programs that rely on self-assessment of these factors.